We assume a weak-perspective camera projection, where the camera pose \(\mathbf {\pi }\)  is parameterized by scale \(\mathbf {s} \in \) , translation \(\mathbf {t} \in ^2\) , and rotation in the form of quaternion \(\mathbf {r} \in ^4\) . We use DIB-R [1]} as our differentiable renderer. We denote \(\mathbf {I} = R(\mathbf {S}, \mathbf {T}, \mathbf {\pi })\)  as the image rendering process.
Similar to previous baselines [2]}, [3]}, [4]}, [5]}, we enforce reflectional symmetry along the \(x\)  axis, which both benefits geometric performance and reduces computation cost.
